1. Field of the Invention
This invention relates to a method and apparatus for continuously packaging in boxes cylindrical-shaped objects manufactured in a production installation.
2. Description of the Prior Art
Two different types of machines for packaging cylindrical-shaped objects such as tubes or empty cases in boxes, operating in accordance with different methods, are being offered in the marketplace. In both types of machines, empty cylindrical-shaped objects, coming in a more or less continuous manner from a production line where they have been produced and printed, reach a machine where they are packed in boxes in which they are forwarded to the factory where they are filled.
In one of the known machines, the cylindrical-shaped objects, stocked in a delivery drum, are conveyed on a slide or inclined piece of sheet metal to a conveyor belt with dividing plates. This belt runs continuously until the desired number of cylindrical-shaped objects is positioned before a pusher. The belt is stopped and a batch of cylindrical-shaped objects is pushed into an auxiliary container or directly into a box, the number of cylindrical-shaped objects being adapted to the dimensions of the box.
In the other known machine, the cylindrical-shaped objects conveyed from a production line are discharged by means of a delivery drum onto an endless conveyor belt made of shells lined up behind each other. The cylindrical-shaped objects in the shells are dumped on a flat conveyor belt and are stopped and pushed together by means of brushes disposed above until the correct number of cylindrical-shaped objects for one layer has been attained, after which the cylindrical-shaped objects are pushed perpendicular to the direction of movement of the belt indirectly or directly into the box.
Both systems have advantages and disadvantages. Although in the first-mentioned machine the cylindrical-shaped objects are treated gently, a change of size in the cylindrical-shaped object requires a set-up time of at least half an hour. In this case, the entire belt with the dividing plates must be changed. In addition to the lost time, there is the considerable added cost of the different, specially designed belts.
The other type of machine can be used for any size cylindrical-shaped object. Only the height of the brush above the conveyor belt must be adapted to the diameter of the cylindrical-shaped objects. However, in this case, the problem is that the guidance of the cylindrical-shaped objects on the flat conveyor belt is not assured. If a cylindrical-shaped object is top-heavy, it may turn and, in this way, upset the order of all of the following cylindrical-shaped objects. A further disadvantage is that the rolls or cases being transported on the flat belt rub against each other and thus are easily scratched. Finally, the operation of this machine has proven to be particularly disadvantageous with cylindrical-shaped objects of laminated plastics which, because of the friction under the brush, can become charged to such a degree that they stick to each other or are completely deformed.